Schizophrenia affects about two million Americans and is seen in people all over the world. It affects both men and women, although men tend to develop the disorder earlier, in early adulthood. Women typically show signs in their twenties and thirties. Early signs can include noticeable changes in behavior. The person may act out in reaction to hallucinations or may withdraw from others. A person with schizophrenia often has difficulty deciphering real from unreal experiences. A sudden onset of severe psychotic psychotic symptoms is called an "acute" phase. Symptoms of hallucinations are referred to as "psychosis." Some people may only experience one episode of psychotic behavior. Chronic schizophrenia describes ongoing symptoms and generally requires long-term treatment.

There is not a single cause of the illness. It appears to have a genetic component. Researchers have known for a long time that it runs in families. Because it is a brain disease, ongoing research is being conducted on brain chemistry and the physical make-up of the brain. There are treatments for schizophrenia, and these have greatly improved over the past few decades. Many people with the illness continue to suffer symptoms, but treatments can reduce the symptoms. Antipsychotic medications are the best treatments currently available, but they do not cure the disease. They can help ease symptoms in some patients, although not all respond well to medications; however, most patients do benefit from treatment.